Goldman Sachs helped the Greek government to mask the true extent of its deficit with the help of a derivatives deal that legally circumvented the EU Maastricht deficit rules. At some point the so-called cross currency swaps will mature, and swell the country's already bloated deficit.

It had worked before. In 2001, just after Greece was admitted to Europe’s monetary union, Goldman helped the government quietly borrow billions, people familiar with the transaction said. That deal, hidden from public view because it was treated as a currency trade rather than a loan, helped Athens to meet Europe’s deficit rules while continuing to spend beyond its means.